Flu symptoms can hit quite suddenly and severely. They usually include fever, chills, headaches and aching muscles. You can often get a cough and sore throat.

Because flu is caused by a virus and not bacteria, antibiotics won't treat it.

Anyone can get flu, but it can be more serious for certain people, such as:

People aged 65 or over

People who have a serious medical condition

Pregnant women

If you are in one of these groups, you're more vulnerable to the effects of flu (even if you're fit and healthy) and could develop flu complications, which are more serious illnesses such as bronchitis and pneumonia, which could result in hospitalisation.